[1] The rock was about one-half mile (0.80 km) east of Pas Yew Islet, which was at 29°57′43″N 121°43′51″E / 29.96194°N 121.73083°E / 29.96194; 121.73083.
In March 1865 a buoy was placed over the rock to warn mariners of its location.
[2] The location of Pas Yew Islet and the other two nearby isles now appear to be inland, under landfill.
Also, the Chinese government placed "torpedoes" (naval mines) at the entrance to the river.
However, the barrier of piles placed across the mouth of the river and the torpedoes laid as defensive measures for the protection of the port had not been removed.